Michael, welcome to the forum. I love the prewar .22/32 S&Ws, both the longer barrel target models and the smaller Kit Guns.
Alan is correct about the broken hammer. You could probably find an adequate replacement for that one without too much trouble if you were so inclined. And yes, those are not the usual extension stocks seen on a .22/32 Target Revolver. They are, however, the stocks that S&W put on their .32 Regulation Police Target Revolver (same frame exactly, aside from the rimfire/centerfire configuration.)
A. Niedner is probably Albert Niedner, born 1899. The other Niedners with a first name beginning with A. that I found were dead by the time this gun was shipped.
Looks to be in good shape, but the exposed end of the hammer stud on the left side of the gun looks just a little flat to me. That sometimes happens when a gun is polished before being reblued. And are the screw holes in the sideplate slightly dished? If so, that would be another indicator of a refinish.
The front sight on your gun is a Sheard bead sight. This is one of several types of sight that S&W could install on target revolvers in the 'teens and 'twenties.
The patent date on the bottom of the stocks deals with the design and mounting of these square butt "Regulation Police" stocks. The basic I-frame is milled with a round butt, and the grip is small. The Regulation Police stocks are square butt, longer and larger. The back of the revolver frame is "rebated" (stepped) so the wood panels can cover the lower half of the backstrap when installed.
Can you let us know the serial number? Use xx for the last two digits if you want to preserve some confidentiality. I'm guessing this gun would be somewhere between 275000 and 310000.